TBI 4.2 running rich? - JeepForum.com
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post #1 of 4 Old 03-12-2011, 03:55 PM Thread Starter
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2000 TJ Wrangler 
Join Date: Feb 2011
Location: reno
Posts: 30
TBI 4.2 running rich?

So I bought this 1990 about a month ago. The PO said it has about 500 miles on this rebuild motor which is when he injected it. It passed smog immediately however since then it has had some problems.

Some pretty potent exhaust fumes in the cab getting much worse (partly due to not having a tailgate bar for my soft top), however it also hesitates at low RPM and misses sometimes at idle.

I know this could be caused by one or several issues and my research so far points to electrical issues. What is throwing me off is that I am obviously not too mechanically inclined and I dont know a whole lot about throttle body injection and what could be causing this.

Any help would be greatly appreciated.

2000 TJ, 4.0, Locked, 4.88's, 35" XTerrains, Warn M8000, Custom this, that and the other.
renowrangler is offline  
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post #2 of 4 Old 01-19-2012, 07:05 PM
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1990 YJ Wrangler 
Join Date: Apr 2011
Location: Colorado springs
Posts: 11

Did you ever find any info on this problem? I have the TBI from an Astro van installed on my 4.2 YJ and its running rich too
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post #3 of 4 Old 01-19-2012, 09:45 PM
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1990 YJ Wrangler 
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Location: The southern armpit of California
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Possible cause of running rich with the TBI:

-bad O2 sensor
-intake/vacuum leak

To start I'd check for any vacuum leaks at the TB gaskets/adapter and at the intake manifold.

Also, check for any codes.
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post #4 of 4 Old 01-20-2012, 08:04 AM
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1988 YJ Wrangler 
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Originally Posted by NonRubicon View Post
Possible cause of running rich with the TBI:

-bad O2 sensor
-intake/vacuum leak

To start I'd check for any vacuum leaks at the TB gaskets/adapter and at the intake manifold.

Also, check for any codes.
What he said! to check for codes put a jumper wire between the A and B terminal of the ALDL connector, turn your ignition to on and count the flashes on your 'check engine light'. Report back here what you find out.
Berniebikes is offline  

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